js实现评分特效

先准备三张图片  empty.png --白色星星图片  用于用户为选择时状态显示   yellow 黄色星星图片 用于用户选择好时显示  green绿色图片用于当用户鼠标在上面移动时显示

body 内容

<ul id="ulStar">

<li></li>

<li></li>

<li></li>

<li></li>

</ul>

 

<style type="text/css">
        #ulStar {
            border:0px solid #0094ff;
            list-style-type:none;
            padding:0px;
            margin:50px auto;
            width:200px;
        }
        #ulStar li{
            border:0px solid #0094ff;
            display:inline;/*变成行内元素*/
            margin:0px;
            padding:6px 13px;
            line-height:30px;/*行高--*/
            background-image:url(/empty.png);
        }
    </style>

 

    <script type="text/javascript">    
        var tt = false;//这个标准用来判断用户是否选择好了评分
        window.onload = function () {
            var liset = document.getElementById("ulStar").children;//获取li标签里面的内容 并且过滤li标签
            for (var i = 0; i < liset.length; i++) {
                liset[i].onmouseover = function () {//当鼠标在上面移动的时候
                    if (tt) return; //如果选择好了就返回 不执行下面代码
                        this.style.backgroundImage = "url(/green.png)";
                        var prate = this.previousElementSibling;//取这个节点前面的兄弟节点
                        while (prate) { //判断兄弟节点
                            prate.style.backgroundImage = "url(/green.png)"; //修改这个兄弟节点的背景图片
                            prate = prate.previousElementSibling; //然后再取这个兄弟节点的前一个兄弟节点
                        }
                    }
                    //鼠标离开的时候
                liset[i].onmouseout = function () {
                    if (tt) return;
                        this.style.backgroundImage = "url(/empty.png)";
                    }
                    //鼠标点击的时候
                    liset[i].onclick = function () {
                    this.style.backgroundImage = "url(/yellow.png)";
                    var prate = this.previousElementSibling;
                    while (prate) {
                        prate.style.backgroundImage = "url(/yellow.png)";
                        prate = prate.previousElementSibling;
                        tt = true;
                    }
                    var prate = this.nextElementSibling //当用户鼠标点击时就取消移动事件 通过这个方法来让用户选择评分
                    while (prate) {
                        prate.style.backgroundImage = "url(/empty.png)";
                        prate = prate.nextElementSibling;
                    }
                } 
            }
        }
    </script>